{"instruction": "You are an expert in named entity recognition. Please extract entities that match the schema definition from the input. Return an empty list if the entity type does not exist. Please respond in the format of a JSON string.", "schema": ["Chemical"], "input": "This study investigated the effect of Oligonol supplementation on circulating levels of prostaglandin E2 ( PGE2 ) and cyclooxygenase ( COX ) - 2 , as well as body temperature , after heat stress in 17 healthy human male volunteers ( age , 21 . 6 +/- 2 . 1 years ) ."}
{"Chemical": ["prostaglandin E2", "PGE2"]}